Ionic conductivity

About: Ionic conductivity is a research topic. Over the lifetime, 19412 publications have been published within this topic receiving 519167 citations.

Ion conducting corn starch biopolymer electrolytes doped with ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate

Abstract: Biodegradable corn starch–lithium hexafluorophosphate (LiPF 6 ) based biopolymer electrolytes were prepared by solution casting technique. Ionic liquid, 1-butyl-3-methylimidazolium hexafluorophosphate (BmImPF 6 ) was doped into the polymer matrix. Upon addition of 50 wt.% BmImPF 6 , the maximum ionic conductivity of (1.47 ± 0.02) × 10 − 4 Scm − 1 was achieved due to its higher amorphous region. This result had been further proven in ATR-FTIR study. Frequency dependence of conductivity and dielectric studies reveal the occurrence of polarization at the electrolyte–electrode interface and thus form the electrical double layer, asserting the non-Debye characteristic of polymer electrolytes. This result is in good agreement with dielectric loss tangent study. Based on the changes in shift, changes in intensity, changes in shape and existence of some new peaks, attenuated total reflectance-Fourier Transform Infrared (ATR-FTIR) divulged the complexation between corn starch, LiPF 6 and BmImPF 6 , as shown in the spectra.

Tailored Li2S–P2S5 glass-ceramic electrolyte by MoS2 doping, possessing high ionic conductivity for all-solid-state lithium-sulfur batteries

Abstract: Tailored synthesis of high-quality solid electrolytes is critical for the development of advanced all-solid-state batteries. Currently, the performance of solid electrolytes is still hindered by low ionic conductivity and poor electrochemical stability. Herein, we report a novel high-quality MoS2-doped Li2S–P2S5 glass-ceramic electrolyte (Li7P2.9S10.85Mo0.01) prepared by a facile combined method of high-energy ball milling plus annealing. Impressively, the obtained Li7P2.9S10.85Mo0.01 exhibits a high ionic conductivity of 4.8 mS cm−1 at room temperature, and a stable wide electrochemical window up to 5 V (vs. Li/Li+). The MoS2-doped electrolyte is demonstrated to have more stability on the lithium metal as compared to the Li7P3S11 counterpart. In addition, all-solid-state Li-S cells are assembled based on the Li7P2.9S10.85Mo0.01 electrolyte and show a high discharge capacity of 1020 mA h g−1, better than that of a cell based on a Li7P3S11 electrolyte. Our study provides a new type of solid electrolyte for the construction of high-performance all-solid-state Li-S batteries.

Nanostructured multi-block copolymer single-ion conductors for safer high-performance lithium batteries

Abstract: The greatest challenges towards the worldwide success of battery-powered electric vehicles revolve around the safety and energy density of the battery. Single-ion conducting polymer electrolytes address both challenges by replacing the flammable and unstable liquid electrolytes and enabling dendrite-free cycling of high-energy lithium metal anodes. To date, however, their commercial use has been hindered by insufficient ionic conductivities at ambient temperature (commonly not exceeding 10−6 S cm−1) and the limited electrochemical stability towards oxidation, in particular when incorporating ether-type building blocks, limiting their application to rather low-voltage cathode materials like LiFePO4. Here, we introduce ether-free, nanostructured multi-block copolymers as single-ion conducting electrolytes, providing high thermal stability and self-extinguishing properties and, if plasticized with ethylene carbonate, ionic conductivities exceeding 10−3 S cm−1 above 30 °C, i.e., approaching that of state-of-the-art liquid electrolytes. Moreover, these single-ion conducting ionomers present highly reversible lithium cycling for more than 1000 h and, as a result of their excellent electrochemical stability, highly stable cycling of Li[Ni1/3Co1/3Mn1/3]O2 cathodes. To the best of our knowledge, this is the first polymer electrolyte that presents such remarkable ionic conductivity and outstanding electrochemical stability towards both reduction and oxidation, thus, paving the way for advanced high-energy lithium metal batteries. Remarkably, the realization of well-defined continuous ionic domains appears to be the key to efficient charge transport through the electrolyte bulk and across the electrode/electrolyte interface, highlighting the importance of the self-assembling nanostructure. The latter is achieved by carefully (i) designing the copolymer structure, i.e., introducing alternating ionic blocks with a very regular distribution of weakly coordinating anions along the polymer chain and rigid blocks, which are completely immiscible with ethylene carbonate, and (ii) choosing the processing solvent, taking into account its interaction with the different copolymer blocks.